<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>DbEnv::dbbackup()</title>
    <link rel="stylesheet" href="apiReference.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Berkeley DB C++ API Reference" />
    <link rel="up" href="env.html" title="Chapter 5.  The DbEnv Handle" />
    <link rel="prev" href="envcreate.html" title="DbEnv" />
    <link rel="next" href="envdbremove.html" title="DbEnv::dbremove()" />
  </head>
  <body>
    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">DbEnv::dbbackup()</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="envcreate.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 5. 
                The DbEnv Handle
        </th>
          <td width="20%" align="right"> <a accesskey="n" href="envdbremove.html">Next</a></td>
        </tr>
      </table>
      <hr />
    </div>
    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="envdbbackup"></a>DbEnv::dbbackup()</h2>
          </div>
        </div>
      </div>
      <pre class="programlisting">#include &lt;db_cxx.h&gt;
 
int
DbEnv::dbbackup(const char *dbfile, const char *target, 
                u_int32_t flags);</pre>
      <p>
        The <code class="methodname">DbEnv::dbbackup()</code> method performs a hot
        backup of a single database file contained within the environment.
    </p>
      <p>
        To back up an entire environment, use the
        <a class="xref" href="envbackup.html" title="DbEnv::backup()">DbEnv::backup()</a>
        method.
    </p>
      <p>
        This method's default behavior can be changed by setting backup
        callbacks. See
        <a class="xref" href="envset_backup_callbacks.html" title="DbEnv::set_backup_callbacks()">DbEnv::set_backup_callbacks()</a>
        for more information. Additional tuning parameters can also be set
        using the 
        <a class="xref" href="envset_backup_config.html" title="DbEnv::set_backup_config()">DbEnv::set_backup_config()</a> method.
    </p>
      <p>
         The <code class="methodname">DbEnv::dbbackup()</code> method may only be
         called after the environment handle has been opened.
    </p>
      <p>
         The <code class="methodname">DbEnv::dbbackup()</code> <span>
            
            <span>
                method either returns a non-zero error value or throws an
                exception that encapsulates a non-zero error value on
                failure, and returns 0 on success.
            </span>
        </span>
    </p>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6651504"></a>Parameters</h3>
            </div>
          </div>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6652104"></a>dbfile</h4>
              </div>
            </div>
          </div>
          <p>
                 Identifies the database file that you want to back up.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6666272"></a>target</h4>
              </div>
            </div>
          </div>
          <p>
                 Identifies the directory in which the back up will be
                 placed.  This target must exist; otherwise this method
                 exits with an <code class="literal">ENOENT</code> error return.
             </p>
          <p>
                 Note that if the backup callbacks are set, then the value
                 specified to this parameter is passed on to the
                 <code class="literal">open_func()</code> callback.  If this
                 parameter is NULL, then the target must be specified
                 directly to the <code class="literal">open_func()</code> callback.
             </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6658880"></a>flags</h4>
              </div>
            </div>
          </div>
          <p>
                The <span class="bold"><strong>flags</strong></span> parameter must
                be set to 0 or the following value:
            </p>
          <div class="itemizedlist">
            <ul type="disc">
              <li>
                <p>
                        <code class="literal">DB_EXCL</code>
                    </p>
                <p>
                        Return an <code class="literal">EEXIST</code> error if a
                        target backup file already exists.
                    </p>
              </li>
            </ul>
          </div>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6668720"></a>Errors</h3>
            </div>
          </div>
        </div>
        <p>
             The <code class="methodname">DbEnv::dbbackup()</code> <span>
            
            <span>
                method may fail and throw a <a class="link" href="dbexception.html" title="Chapter 6. The DbException Class">DbException</a> 
                exception, encapsulating one of the following non-zero errors, or return one
                of the following non-zero errors:
            </span>
        </span>
        </p>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6677600"></a>EEXIST</h4>
              </div>
            </div>
          </div>
          <p>
                <code class="literal">DB_EXCL</code> was specified for the
                <code class="literal">flags</code> parameter, and an existing target
                file was discovered when attempting to back up a source
                file.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6673584"></a>ENOENT</h4>
              </div>
            </div>
          </div>
          <p>
                The target directory does not exist.
            </p>
        </div>
        <div class="sect3" lang="en" xml:lang="en">
          <div class="titlepage">
            <div>
              <div>
                <h4 class="title"><a id="idp6677816"></a>EINVAL</h4>
              </div>
            </div>
          </div>
          <p>
                An invalid flag value or parameter was specified.
            </p>
        </div>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6643488"></a>Class</h3>
            </div>
          </div>
        </div>
        <p>
            <a class="link" href="env.html" title="Chapter 5.  The DbEnv Handle">DbEnv</a>  
        </p>
      </div>
      <div class="sect2" lang="en" xml:lang="en">
        <div class="titlepage">
          <div>
            <div>
              <h3 class="title"><a id="idp6644328"></a>See Also</h3>
            </div>
          </div>
        </div>
        <p>
             <a class="xref" href="env.html#envlist" title="Database Environments and Related Methods">Database Environments and Related Methods</a> 
        </p>
      </div>
    </div>
    <div class="navfooter">
      <hr />
      <table width="100%" summary="Navigation footer">
        <tr>
          <td width="40%" align="left"><a accesskey="p" href="envcreate.html">Prev</a> </td>
          <td width="20%" align="center">
            <a accesskey="u" href="env.html">Up</a>
          </td>
          <td width="40%" align="right"> <a accesskey="n" href="envdbremove.html">Next</a></td>
        </tr>
        <tr>
          <td width="40%" align="left" valign="top">DbEnv </td>
          <td width="20%" align="center">
            <a accesskey="h" href="index.html">Home</a>
          </td>
          <td width="40%" align="right" valign="top"> DbEnv::dbremove()</td>
        </tr>
      </table>
    </div>
  </body>
</html>
